It is estimated that between 5% and 10% of patients admitted to hospitals acquire one or more healthcare-associated infections, which leads to more than a million people worldwide being affected by infections acquired in hospitals. Health-care associated infections are also an important problem in extended care facilities, including nursing homes and rehabilitations units. These health-care acquired infections are associated with nearly 100,000 deaths annularly.
Patients infected with healthcare-associated microbes frequently contaminate items in their immediate vicinity with microbes that may remain viable on surfaces for days to weeks. Contaminated surfaces in healthcare facilities contribute to the spread of healthcare-associated microbes. In some instances, patients acquire microbes following direct contact with contaminated equipment or other surfaces. Contaminated surfaces can act as sources from which healthcare workers contaminate their hands. Healthcare workers can contaminate their hands by touching contaminated surfaces, and can transmit microbes if their hands are not cleansed appropriately.
Inadequate cleaning of rooms after discharging a patient with certain contagious diseases put subsequent patients admitted to the room at risk of acquiring the organism. Routine cleaning of patient rooms is often below the required standard. Therefore, improved cleaning and disinfection of the environment can reduce the risk of patients acquiring multi-drug resistant pathogens. Cleaning, disinfecting and sterilization save lives and improves patient outcomes. Providing patients with a safe environment of care requires appropriate cleaning and disinfection of medical equipment and environmental surfaces.
Thus, the use of ultraviolet (UV) lighting systems has become well known for disinfecting, sanitizing and sterilizing environments. Most commercially available lighting systems with antimicrobial functions combine various inorganic and organic based antimicrobial materials (AM) as additives blended into conventional materials, for example, polymethylmethacrylate (PMMA), polycarbonate (PC) and polyethylene (PE), etc. for lighting components such as diffusers to inhibit the growth of microbes on their outer surfaces. However, due to the intrinsic inhibition mechanism from the AM, a certain humidity level is required and the AM efficacy is reduced due to the accumulation of damaged microbes on the surface. Therefore, frequent cleaning is required every 3-4 days.
One commonly known cleaning technique is exposing titanium dioxide photocatalyst coating to UV light to provide a purifying coating process based on the science of photocatalysis. The principle of photocatalysis is to accelerate nature's cleaning and purifying process using light as energy. Photocatalyst coating is a “green” technology that can be applied on walls, ceiling, floor carpets, curtains, car interior, et seats, etc. and all kinds of surface to form an invisible film. The film can work all day to decompose all kinds or micro-organic matters, like bacteria, viruses, mold, formaldehyde, benzene, xylene, ammonia, VOCs, tough odors, etc.
With a constant amount of light provided, titanium dioxide photocatalyst an control and prevent growth of bacteria, germ, and mold. Any bacteria and germ can be killed and decomposed in environments such as hospitals, schools, public restrooms, restaurants, bars, club houses, theaters, daycare centers, convention centers, stadiums, and casinos.
Titanium dioxide is a safe and stable substance. Numerous applications have been developed from utilizing its photocatalytic reaction properties. Employing a light-catalyst or photocatalyst, titanium dioxide breaks down organic compounds and acts as both a sterilizer and deodorizer. Photocatalyst coating can transform any surface into self-cleaning, anti-bacterial, anti-fungal, and mold free surface. The hydrophilic property (or high water-affinity) of titanium dioxide, coupled with gravity, makes the coating self-cleaning.
Titanium dioxide photocatalyst coating has been proven to clean air and kill microbes by photocatalytic oxidation and the hydrophilic surface also enables easy cleaning. However, it has limited use in areas where at times there can be less UVA in the night or total absence of UVA during unused hours.